Wireless charging systems are becoming ubiquitous in today's society. For example, many smartphones and wearables implement wireless charging technology. Ease of use, greater reliability, spatial freedom, reduced connectors and openings, and the possibility of hermetically sealing are among the benefits offered by wireless charging. Standards, such as Qi standard from the Wireless Power Consortium are becoming popular.
High power devices such as power tools, rugged notebook computers, medical instruments, factory automation systems, drones, and even robotic vacuums can benefit from the type of wireless charging seen on devices such as wearables and smartphones. However, batteries in high power devices have much greater capacities and require higher charging rates in order to charge the device in a reasonable time. The charging rate required by high power devices starts at 30 W, but may reach up to 100 W or more.
There are many challenges in managing and providing high power levels through a wireless interface, such as efficiency, metallic Foreign Object Detection (FOD) and Electromagnetic Interference (EMI). Many of these challenges are critical to a working and safe system. Physics imposes limits on what can be accomplished using common circuit topologies and transmitter/receiver architectures, but the key is to pick an implementation that provides sufficient efficiency and safe operation at a reasonable overall cost.